Channel state information transmission in a wireless network

ABSTRACT

A wireless device receives a downlink control information comprising a first field and a second field. The wireless device determines a position of a first subframe in one or more subframes employing the first field. The wireless device transmits, in the first subframe, one or more channel state information (CSI) fields when the second field is set to trigger a CSI report.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 62/313,771, filed Mar. 27, 2016, which is hereby incorporated by reference in their entirety.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Examples of several of the various embodiments of the present disclosure are described herein with reference to the drawings.

FIG. 1 is a diagram depicting example sets of OFDM subcarriers as per an aspect of an embodiment of the present disclosure.

FIG. 2 is a diagram depicting an example transmission time and reception time for two carriers in a carrier group as per an aspect of an embodiment of the present disclosure.

FIG. 3 is an example diagram depicting OFDM radio resources as per an aspect of an embodiment of the present disclosure.

FIG. 4 is an example block diagram of a base station and a wireless device as per an aspect of an embodiment of the present disclosure.

FIG. 5A, FIG. 5B, FIG. 5C and FIG. 5D are example diagrams for uplink and downlink signal transmission as per an aspect of an embodiment of the present disclosure.

FIG. 6 is an example diagram for a protocol structure with CA and DC as per an aspect of an embodiment of the present disclosure.

FIG. 7 is an example diagram for a protocol structure with CA and DC as per an aspect of an embodiment of the present disclosure.

FIG. 8 shows example TAG configurations as per an aspect of an embodiment of the present disclosure.

FIG. 9 is an example message flow in a random access process in a secondary TAG as per an aspect of an embodiment of the present disclosure.

FIG. 10 is an example diagram depicting a downlink burst as per an aspect of an embodiment of the present disclosure.

FIG. 11 is an example diagram depicting a plurality of cells as per an aspect of an embodiment of the present disclosure.

FIG. 12 is an example diagram depicting listen before talk procedures as per an aspect of an embodiment of the present disclosure.

FIG. 13 is an example flow diagram illustrating an aspect of an embodiment of the present disclosure.

FIG. 14 is an example flow diagram illustrating an aspect of an embodiment of the present disclosure.

FIG. 15 is an example flow diagram illustrating an aspect of an embodiment of the present disclosure.

FIG. 16 is an example DCI fields as per an aspect of an embodiment of the present disclosure.

FIG. 17 is an example flow diagram illustrating an aspect of an embodiment of the present disclosure.

FIG. 18 is an example flow diagram illustrating an aspect of an embodiment of the present disclosure.

FIG. 19 is an example flow diagram illustrating an aspect of an embodiment of the present disclosure.

FIG. 20 is an example configuration table an aspect of an embodiment of the present disclosure.

FIG. 21 is an example configuration table an aspect of an embodiment of the present disclosure.

FIG. 22 is an example configuration table an aspect of an embodiment of the present disclosure.

FIG. 23 is an example configuration table an aspect of an embodiment of the present disclosure.

FIG. 24 is an example configuration table an aspect of an embodiment of the present disclosure.

FIG. 25 is an example configuration table an aspect of an embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Example embodiments of the present disclosure enable operation of carrier aggregation. Embodiments of the technology disclosed herein may be employed in the technical field of multicarrier communication systems.

The following Acronyms are used throughout the present disclosure:

-   -   ASIC application-specific integrated circuit     -   BPSK binary phase shift keying     -   CA carrier aggregation     -   CSI channel state information     -   CDMA code division multiple access     -   CSS common search space     -   CPLD complex programmable logic devices     -   CC component carrier     -   DL downlink     -   DCI downlink control information     -   DC dual connectivity     -   EPC evolved packet core     -   E-UTRAN evolved-universal terrestrial radio access network     -   FPGA field programmable gate arrays     -   FDD frequency division multiplexing     -   HDL hardware description languages     -   HARQ hybrid automatic repeat request     -   IE information element     -   LAA licensed assisted access     -   LTE long term evolution     -   MCG master cell group     -   MeNB master evolved node B     -   MIB master information block     -   MAC media access control     -   MAC media access control     -   MME mobility management entity     -   NAS non-access stratum     -   OFDM orthogonal frequency division multiplexing     -   PDCP packet data convergence protocol     -   PDU packet data unit     -   PHY physical     -   PDCCH physical downlink control channel     -   PHICH physical HARQ indicator channel     -   PUCCH physical uplink control channel     -   PUSCH physical uplink shared channel     -   PCell primary cell     -   PCell primary cell     -   PCC primary component carrier     -   PSCell primary secondary cell     -   pTAG primary timing advance group     -   QAM quadrature amplitude modulation     -   QPSK quadrature phase shift keying     -   RBG Resource Block Groups     -   RLC radio link control     -   RRC radio resource control     -   RA random access     -   RB resource blocks     -   SCC secondary component carrier     -   SCell secondary cell     -   Scell secondary cells     -   SCG secondary cell group     -   SeNB secondary evolved node B     -   sTAGs secondary timing advance group     -   SDU service data unit     -   S-GW serving gateway     -   SRB signaling radio bearer     -   SC-OFDM single carrier-OFDM     -   SFN system frame number     -   SIB system information block     -   TAI tracking area identifier     -   TAT time alignment timer     -   TDD time division duplexing     -   TDMA time division multiple access     -   TA timing advance     -   TAG timing advance group     -   TB transport block     -   UL uplink     -   UE user equipment     -   VHDL VHSIC hardware description language

Example embodiments of the disclosure may be implemented using various physical layer modulation and transmission mechanisms. Example transmission mechanisms may include, but are not limited to: CDMA, OFDM, TDMA, Wavelet technologies, and/or the like. Hybrid transmission mechanisms such as TDMA/CDMA, and OFDM/CDMA may also be employed. Various modulation schemes may be applied for signal transmission in the physical layer. Examples of modulation schemes include, but are not limited to: phase, amplitude, code, a combination of these, and/or the like. An example radio transmission method may implement QAM using BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, and/or the like. Physical radio transmission may be enhanced by dynamically or semi-dynamically changing the modulation and coding scheme depending on transmission requirements and radio conditions.

FIG. 1 is a diagram depicting example sets of OFDM subcarriers as per an aspect of an embodiment of the present disclosure. As illustrated in this example, arrow(s) in the diagram may depict a subcarrier in a multicarrier OFDM system. The OFDM system may use technology such as OFDM technology, DFTS-OFDM, SC-OFDM technology, or the like. For example, arrow 101 shows a subcarrier transmitting information symbols. FIG. 1 is for illustration purposes, and a typical multicarrier OFDM system may include more subcarriers in a carrier. For example, the number of subcarriers in a carrier may be in the range of 10 to 10,000 subcarriers. FIG. 1 shows two guard bands 106 and 107 in a transmission band. As illustrated in FIG. 1, guard band 106 is between subcarriers 103 and subcarriers 104. The example set of subcarriers A 102 includes subcarriers 103 and subcarriers 104. FIG. 1 also illustrates an example set of subcarriers B 105. As illustrated, there is no guard band between any two subcarriers in the example set of subcarriers B 105. Carriers in a multicarrier OFDM communication system may be contiguous carriers, non-contiguous carriers, or a combination of both contiguous and non-contiguous carriers.

FIG. 2 is a diagram depicting an example transmission time and reception time for two carriers as per an aspect of an embodiment of the present disclosure. A multicarrier OFDM communication system may include one or more carriers, for example, ranging from 1 to 10 carriers. Carrier A 204 and carrier B 205 may have the same or different timing structures. Although FIG. 2 shows two synchronized carriers, carrier A 204 and carrier B 205 may or may not be synchronized with each other. Different radio frame structures may be supported for FDD and TDD duplex mechanisms. FIG. 2 shows an example FDD frame timing. Downlink and uplink transmissions may be organized into radio frames 201. In this example, the radio frame duration is 10 msec. Other frame durations, for example, in the range of 1 to 100 msec may also be supported. In this example, each 10 ms radio frame 201 may be divided into ten equally sized subframes 202. Other subframe durations such as 0.5 msec, 1 msec, 2 msec, and 5 msec may also be supported. Subframe(s) may consist of two or more slots (for example, slots 206 and 207). For the example of FDD, 10 subframes may be available for downlink transmission and 10 subframes may be available for uplink transmissions in each 10 ms interval. Uplink and downlink transmissions may be separated in the frequency domain. Slot(s) may include a plurality of OFDM symbols 203. The number of OFDM symbols 203 in a slot 206 may depend on the cyclic prefix length and subcarrier spacing.

FIG. 3 is a diagram depicting OFDM radio resources as per an aspect of an embodiment of the present disclosure. The resource grid structure in time 304 and frequency 305 is illustrated in FIG. 3. The quantity of downlink subcarriers or RBs (in this example 6 to 100 RBs) may depend, at least in part, on the downlink transmission bandwidth 306 configured in the cell. The smallest radio resource unit may be called a resource element (e.g. 301). Resource elements may be grouped into resource blocks (e.g. 302). Resource blocks may be grouped into larger radio resources called Resource Block Groups (RBG) (e.g. 303). The transmitted signal in slot 206 may be described by one or several resource grids of a plurality of subcarriers and a plurality of OFDM symbols. Resource blocks may be used to describe the mapping of certain physical channels to resource elements. Other pre-defined groupings of physical resource elements may be implemented in the system depending on the radio technology. For example, 24 subcarriers may be grouped as a radio block for a duration of 5 msec. In an illustrative example, a resource block may correspond to one slot in the time domain and 180 kHz in the frequency domain (for 15 KHz subcarrier bandwidth and 12 subcarriers).

FIG. 5A, FIG. 5B, FIG. 5C and FIG. 5D are example diagrams for uplink and downlink signal transmission as per an aspect of an embodiment of the present disclosure. FIG. 5A shows an example uplink physical channel. The baseband signal representing the physical uplink shared channel may perform the following processes. These functions are illustrated as examples and it is anticipated that other mechanisms may be implemented in various embodiments. The functions may comprise scrambling, modulation of scrambled bits to generate complex-valued symbols, mapping of the complex-valued modulation symbols onto one or several transmission layers, transform precoding to generate complex-valued symbols, precoding of the complex-valued symbols, mapping of precoded complex-valued symbols to resource elements, generation of complex-valued time-domain DFTS-OFDM/SC-FDMA signal for each antenna port, and/or the like.

Example modulation and up-conversion to the carrier frequency of the complex-valued DFTS-OFDM/SC-FDMA baseband signal for each antenna port and/or the complex-valued PRACH baseband signal is shown in FIG. 5B. Filtering may be employed prior to transmission.

An example structure for Downlink Transmissions is shown in FIG. 5C. The baseband signal representing a downlink physical channel may perform the following processes. These functions are illustrated as examples and it is anticipated that other mechanisms may be implemented in various embodiments. The functions include scrambling of coded bits in each of the codewords to be transmitted on a physical channel; modulation of scrambled bits to generate complex-valued modulation symbols; mapping of the complex-valued modulation symbols onto one or several transmission layers; precoding of the complex-valued modulation symbols on each layer for transmission on the antenna ports; mapping of complex-valued modulation symbols for each antenna port to resource elements; generation of complex-valued time-domain OFDM signal for each antenna port, and/or the like.

Example modulation and up-conversion to the carrier frequency of the complex-valued OFDM baseband signal for each antenna port is shown in FIG. 5D. Filtering may be employed prior to transmission.

FIG. 4 is an example block diagram of a base station 401 and a wireless device 406, as per an aspect of an embodiment of the present disclosure. A communication network 400 may include at least one base station 401 and at least one wireless device 406. The base station 401 may include at least one communication interface 402, at least one processor 403, and at least one set of program code instructions 405 stored in non-transitory memory 404 and executable by the at least one processor 403. The wireless device 406 may include at least one communication interface 407, at least one processor 408, and at least one set of program code instructions 410 stored in non-transitory memory 409 and executable by the at least one processor 408. Communication interface 402 in base station 401 may be configured to engage in communication with communication interface 407 in wireless device 406 via a communication path that includes at least one wireless link 411. Wireless link 411 may be a bi-directional link. Communication interface 407 in wireless device 406 may also be configured to engage in a communication with communication interface 402 in base station 401. Base station 401 and wireless device 406 may be configured to send and receive data over wireless link 411 using multiple frequency carriers. According to aspects of an embodiments, transceiver(s) may be employed. A transceiver is a device that includes both a transmitter and receiver. Transceivers may be employed in devices such as wireless devices, base stations, relay nodes, and/or the like. Example embodiments for radio technology implemented in communication interface 402, 407 and wireless link 411 are illustrated are FIG. 1, FIG. 2, FIG. 3, FIG. 5, and associated text.

An interface may be a hardware interface, a firmware interface, a software interface, and/or a combination thereof. The hardware interface may include connectors, wires, electronic devices such as drivers, amplifiers, and/or the like. A software interface may include code stored in a memory device to implement protocol(s), protocol layers, communication drivers, device drivers, combinations thereof, and/or the like. A firmware interface may include a combination of embedded hardware and code stored in and/or in communication with a memory device to implement connections, electronic device operations, protocol(s), protocol layers, communication drivers, device drivers, hardware operations, combinations thereof, and/or the like.

The term configured may relate to the capacity of a device whether the device is in an operational or non-operational state. Configured may also refer to specific settings in a device that effect the operational characteristics of the device whether the device is in an operational or non-operational state. In other words, the hardware, software, firmware, registers, memory values, and/or the like may be “configured” within a device, whether the device is in an operational or nonoperational state, to provide the device with specific characteristics. Terms such as “a control message to cause in a device” may mean that a control message has parameters that may be used to configure specific characteristics in the device, whether the device is in an operational or non-operational state.

According to various aspects of an embodiment, an LTE network may include a multitude of base stations, providing a user plane PDCP/RLC/MAC/PHY and control plane (RRC) protocol terminations towards the wireless device. The base station(s) may be interconnected with other base station(s) (for example, interconnected employing an X2 interface). Base stations may also be connected employing, for example, an S1 interface to an EPC. For example, base stations may be interconnected to the MME employing the S1-MME interface and to the S-G) employing the S1-U interface. The S1 interface may support a many-to-many relation between MMEs/Serving Gateways and base stations. A base station may include many sectors for example: 1, 2, 3, 4, or 6 sectors. A base station may include many cells, for example, ranging from 1 to 50 cells or more. A cell may be categorized, for example, as a primary cell or secondary cell. At RRC connection establishment/re-establishment/handover, one serving cell may provide the NAS (non-access stratum) mobility information (e.g. TAI), and at RRC connection re-establishment/handover, one serving cell may provide the security input. This cell may be referred to as the Primary Cell (PCell). In the downlink, the carrier corresponding to the PCell may be the Downlink Primary Component Carrier (DL PCC), while in the uplink, the carrier corresponding to the PCell may be the Uplink Primary Component Carrier (UL PCC). Depending on wireless device capabilities, Secondary Cells (SCells) may be configured to form together with the PCell a set of serving cells. In the downlink, the carrier corresponding to an SCell may be a Downlink Secondary Component Carrier (DL SCC), while in the uplink, it may be an Uplink Secondary Component Carrier (UL SCC). An SCell may or may not have an uplink carrier.

A cell, comprising a downlink carrier and optionally an uplink carrier, may be assigned a physical cell ID and a cell index. A carrier (downlink or uplink) may belong to only one cell. The cell ID or Cell index may also identify the downlink carrier or uplink carrier of the cell (depending on the context it is used). In the specification, cell ID may be equally referred to a carrier ID, and cell index may be referred to carrier index. In implementation, the physical cell ID or cell index may be assigned to a cell. A cell ID may be determined using a synchronization signal transmitted on a downlink carrier. A cell index may be determined using RRC messages. For example, when the specification refers to a first physical cell ID for a first downlink carrier, the specification may mean the first physical cell ID is for a cell comprising the first downlink carrier. The same concept may apply, for example, to carrier activation. When the specification indicates that a first carrier is activated, the specification may also mean that the cell comprising the first carrier is activated.

Embodiments may be configured to operate as needed. The disclosed mechanism may be performed when certain criteria are met, for example, in a wireless device, a base station, a radio environment, a network, a combination of the above, and/or the like. Example criteria may be based, at least in part, on for example, traffic load, initial system set up, packet sizes, traffic characteristics, a combination of the above, and/or the like. When the one or more criteria are met, various example embodiments may be applied. Therefore, it may be possible to implement example embodiments that selectively implement disclosed protocols.

A base station may communicate with a mix of wireless devices. Wireless devices may support multiple technologies, and/or multiple releases of the same technology. Wireless devices may have some specific capability(ies) depending on its wireless device category and/or capability(ies). A base station may comprise multiple sectors. When this disclosure refers to a base station communicating with a plurality of wireless devices, this disclosure may refer to a subset of the total wireless devices in a coverage area. This disclosure may refer to, for example, a plurality of wireless devices of a given LTE release with a given capability and in a given sector of the base station. The plurality of wireless devices in this disclosure may refer to a selected plurality of wireless devices, and/or a subset of total wireless devices in a coverage area which perform according to disclosed methods, and/or the like. There may be a plurality of wireless devices in a coverage area that may not comply with the disclosed methods, for example, because those wireless devices perform based on older releases of LTE technology.

FIG. 6 and FIG. 7 are example diagrams for protocol structure with CA and DC as per an aspect of an embodiment of the present disclosure. E-UTRAN may support Dual Connectivity (DC) operation whereby a multiple RX/TX UE in RRC_CONNECTED may be configured to utilize radio resources provided by two schedulers located in two eNBs connected via a non-ideal backhaul over the X2 interface. eNBs involved in DC for a certain UE may assume two different roles: an eNB may either act as an MeNB or as an SeNB. In DC a UE may be connected to one MeNB and one SeNB. Mechanisms implemented in DC may be extended to cover more than two eNBs. FIG. 7 illustrates one example structure for the UE side MAC entities when a Master Cell Group (MCG) and a Secondary Cell Group (SCG) are configured, and it may not restrict implementation. Media Broadcast Multicast Service (MBMS) reception is not shown in this figure for simplicity.

In DC, the radio protocol architecture that a particular bearer uses may depend on how the bearer is setup. Three alternatives may exist, an MCG bearer, an SCG bearer and a split bearer as shown in FIG. 6. RRC may be located in MeNB and SRBs may be configured as a MCG bearer type and may use the radio resources of the MeNB. DC may also be described as having at least one bearer configured to use radio resources provided by the SeNB. DC may or may not be configured/implemented in example embodiments of the disclosure.

In the case of DC, the UE may be configured with two MAC entities: one MAC entity for MeNB, and one MAC entity for SeNB. In DC, the configured set of serving cells for a UE may comprise two subsets: the Master Cell Group (MCG) containing the serving cells of the MeNB, and the Secondary Cell Group (SCG) containing the serving cells of the SeNB. For a SCG, one or more of the following may be applied. At least one cell in the SCG may have a configured UL CC and one of them, named PSCell (or PCell of SCG, or sometimes called PCell), may be configured with PUCCH resources. When the SCG is configured, there may be at least one SCG bearer or one Split bearer. Upon detection of a physical layer problem or a random access problem on a PSCell, or the maximum number of RLC retransmissions has been reached associated with the SCG, or upon detection of an access problem on a PSCell during a SCG addition or a SCG change: a RRC connection re-establishment procedure may not be triggered, UL transmissions towards cells of the SCG may be stopped, and a MeNB may be informed by the UE of a SCG failure type. For split bearer, the DL data transfer over the MeNB may be maintained. The RLC AM bearer may be configured for the split bearer. Like a PCell, a PSCell may not be de-activated. A PSCell may be changed with a SCG change (for example, with a security key change and a RACH procedure), and/or neither a direct bearer type change between a Split bearer and a SCG bearer nor simultaneous configuration of a SCG and a Split bearer may be supported.

With respect to the interaction between a MeNB and a SeNB, one or more of the following principles may be applied. The MeNB may maintain the RRM measurement configuration of the UE and may, (for example, based on received measurement reports or traffic conditions or bearer types), decide to ask a SeNB to provide additional resources (serving cells) for a UE. Upon receiving a request from the MeNB, a SeNB may create a container that may result in the configuration of additional serving cells for the UE (or decide that it has no resource available to do so). For UE capability coordination, the MeNB may provide (part of) the AS configuration and the UE capabilities to the SeNB. The MeNB and the SeNB may exchange information about a UE configuration by employing RRC containers (inter-node messages) carried in X2 messages. The SeNB may initiate a reconfiguration of its existing serving cells (for example, a PUCCH towards the SeNB). The SeNB may decide which cell is the PSCell within the SCG. The MeNB may not change the content of the RRC configuration provided by the SeNB. In the case of a SCG addition and a SCG SCell addition, the MeNB may provide the latest measurement results for the SCG cell(s). Both a MeNB and a SeNB may know the SFN and subframe offset of each other by OAM, (for example, for the purpose of DRX alignment and identification of a measurement gap). In an example, when adding a new SCG SCell, dedicated RRC signaling may be used for sending required system information of the cell as for CA, except for the SFN acquired from a MIB of the PSCell of a SCG.

In an example, serving cells may be grouped in a TA group (TAG). Serving cells in one TAG may use the same timing reference. For a given TAG, user equipment (UE) may use at least one downlink carrier as a timing reference. For a given TAG, a UE may synchronize uplink subframe and frame transmission timing of uplink carriers belonging to the same TAG. In an example, serving cells having an uplink to which the same TA applies may correspond to serving cells hosted by the same receiver. A UE supporting multiple TAs may support two or more TA groups. One TA group may contain the PCell and may be called a primary TAG (pTAG). In a multiple TAG configuration, at least one TA group may not contain the PCell and may be called a secondary TAG (sTAG). In an example, carriers within the same TA group may use the same TA value and/or the same timing reference. When DC is configured, cells belonging to a cell group (MCG or SCG) may be grouped into multiple TAGs including a pTAG and one or more sTAGs.

FIG. 8 shows example TAG configurations as per an aspect of an embodiment of the present disclosure. In Example 1, pTAG comprises a PCell, and an sTAG comprises SCell1. In Example 2, a pTAG comprises a PCell and SCell1, and an sTAG comprises SCell2 and SCell3. In Example 3, pTAG comprises PCell and SCell1, and an sTAG1 includes SCell2 and SCell3, and sTAG2 comprises SCell4. Up to four TAGs may be supported in a cell group (MCG or SCG) and other example TAG configurations may also be provided. In various examples in this disclosure, example mechanisms are described for a pTAG and an sTAG. Some of the example mechanisms may be applied to configurations with multiple sTAGs.

In an example, an eNB may initiate an RA procedure via a PDCCH order for an activated SCell. This PDCCH order may be sent on a scheduling cell of this SCell. When cross carrier scheduling is configured for a cell, the scheduling cell may be different than the cell that is employed for preamble transmission, and the PDCCH order may include an SCell index. At least a non-contention based RA procedure may be supported for SCell(s) assigned to sTAG(s).

FIG. 9 is an example message flow in a random access process in a secondary TAG as per an aspect of an embodiment of the present disclosure. An eNB transmits an activation command 600 to activate an SCell. A preamble 602 (Msg1) may be sent by a UE in response to a PDCCH order 601 on an SCell belonging to an sTAG. In an example embodiment, preamble transmission for SCells may be controlled by the network using PDCCH format 1A. Msg2 message 603 (RAR: random access response) in response to the preamble transmission on the SCell may be addressed to RA-RNTI in a PCell common search space (CSS). Uplink packets 604 may be transmitted on the SCell in which the preamble was transmitted.

According to an embodiment, initial timing alignment may be achieved through a random access procedure. This may involve a UE transmitting a random access preamble and an eNB responding with an initial TA command NTA (amount of timing advance) within a random access response window. The start of the random access preamble may be aligned with the start of a corresponding uplink subframe at the UE assuming NTA=0. The eNB may estimate the uplink timing from the random access preamble transmitted by the UE. The TA command may be derived by the eNB based on the estimation of the difference between the desired UL timing and the actual UL timing. The UE may determine the initial uplink transmission timing relative to the corresponding downlink of the sTAG on which the preamble is transmitted.

The mapping of a serving cell to a TAG may be configured by a serving eNB with RRC signaling. The mechanism for TAG configuration and reconfiguration may be based on RRC signaling. According to various aspects of an embodiment, when an eNB performs an SCell addition configuration, the related TAG configuration may be configured for the SCell. In an example embodiment, an eNB may modify the TAG configuration of an SCell by removing (releasing) the SCell and adding(configuring) a new SCell (with the same physical cell ID and frequency) with an updated TAG ID. The new SCell with the updated TAG ID may initially be inactive subsequent to being assigned the updated TAG ID. The eNB may activate the updated new SCell and start scheduling packets on the activated SCell. In an example implementation, it may not be possible to change the TAG associated with an SCell, but rather, the SCell may need to be removed and a new SCell may need to be added with another TAG. For example, if there is a need to move an SCell from an sTAG to a pTAG, at least one RRC message, (for example, at least one RRC reconfiguration message), may be send to the UE to reconfigure TAG configurations by releasing the SCell and then configuring the SCell as a part of the pTAG. When an SCell is added/configured without a TAG index, the SCell may be explicitly assigned to the pTAG. The PCell may not change its TA group and may be a member of the pTAG.

The purpose of an RRC connection reconfiguration procedure may be to modify an RRC connection, (for example, to establish, modify and/or release RBs, to perform handover, to setup, modify, and/or release measurements, to add, modify, and/or release SCells). If the received RRC Connection Reconfiguration message includes the sCellToReleaseList, the UE may perform an SCell release. If the received RRC Connection Reconfiguration message includes the sCellToAddModList, the UE may perform SCell additions or modification.

In LTE Release-10 and Release-11 CA, a PUCCH may only be transmitted on the PCell (PSCell) to an eNB. In LTE-Release 12 and earlier, a UE may transmit PUCCH information on one cell (PCell or PSCell) to a given eNB.

As the number of CA capable UEs and also the number of aggregated carriers increase, the number of PUCCHs and also the PUCCH payload size may increase. Accommodating the PUCCH transmissions on the PCell may lead to a high PUCCH load on the PCell. A PUCCH on an SCell may be introduced to offload the PUCCH resource from the PCell. More than one PUCCH may be configured for example, a PUCCH on a PCell and another PUCCH on an SCell. In the example embodiments, one, two or more cells may be configured with PUCCH resources for transmitting CSI/ACK/NACK to a base station. Cells may be grouped into multiple PUCCH groups, and one or more cell within a group may be configured with a PUCCH. In an example configuration, one SCell may belong to one PUCCH group. SCells with a configured PUCCH transmitted to a base station may be called a PUCCH SCell, and a cell group with a common PUCCH resource transmitted to the same base station may be called a PUCCH group.

In an example embodiment, a MAC entity may have a configurable timer timeAlignmentTimer per TAG. The timeAlignmentTimer may be used to control how long the MAC entity considers the Serving Cells belonging to the associated TAG to be uplink time aligned. The MAC entity may, when a Timing Advance Command MAC control element is received, apply the Timing Advance Command for the indicated TAG; start or restart the timeAlignmentTimer associated with the indicated TAG. The MAC entity may, when a Timing Advance Command is received in a Random Access Response message for a serving cell belonging to a TAG and/or if the Random Access Preamble was not selected by the MAC entity, apply the Timing Advance Command for this TAG and start or restart the timeAlignmentTimer associated with this TAG. Otherwise, if the timeAlignmentTimer associated with this TAG is not running, the Timing Advance Command for this TAG may be applied and the timeAlignmentTimer associated with this TAG started. When the contention resolution is considered not successful, a timeAlignmentTimer associated with this TAG may be stopped. Otherwise, the MAC entity may ignore the received Timing Advance Command.

In example embodiments, a timer is running once it is started, until it is stopped or until it expires; otherwise it may not be running. A timer can be started if it is not running or restarted if it is running. For example, a timer may be started or restarted from its initial value.

Example embodiments of the disclosure may enable operation of multi-carrier communications. Other example embodiments may comprise a non-transitory tangible computer readable media comprising instructions executable by one or more processors to cause operation of multi-carrier communications. Yet other example embodiments may comprise an article of manufacture that comprises a non-transitory tangible computer readable machine-accessible medium having instructions encoded thereon for enabling programmable hardware to cause a device (e.g. wireless communicator, UE, base station, etc.) to enable operation of multi-carrier communications. The device may include processors, memory, interfaces, and/or the like. Other example embodiments may comprise communication networks comprising devices such as base stations, wireless devices (or user equipment: UE), servers, switches, antennas, and/or the like.

The amount of data traffic carried over cellular networks is expected to increase for many years to come. The number of users/devices is increasing and each user/device accesses an increasing number and variety of services, e.g. video delivery, large files, images. This may require not only high capacity in the network, but also provisioning very high data rates to meet customers' expectations on interactivity and responsiveness. More spectrum may therefore needed for cellular operators to meet the increasing demand. Considering user expectations of high data rates along with seamless mobility, it may be beneficial that more spectrum be made available for deploying macro cells as well as small cells for cellular systems.

Striving to meet the market demands, there has been increasing interest from operators in deploying some complementary access utilizing unlicensed spectrum to meet the traffic growth. This is exemplified by the large number of operator-deployed Wi-Fi networks and the 3GPP standardization of LTE/WLAN interworking solutions. This interest indicates that unlicensed spectrum, when present, may be an effective complement to licensed spectrum for cellular operators to help addressing the traffic explosion in some scenarios, such as hotspot areas. LAA may offer an alternative for operators to make use of unlicensed spectrum while managing one radio network, thus offering new possibilities for optimizing the network's efficiency.

In an example embodiment, Listen-before-talk (clear channel assessment) may be implemented for transmission in an LAA cell. In a listen-before-talk (LBT) procedure, equipment may apply a clear channel assessment (CCA) check before using the channel. For example, the CCA may utilize at least energy detection to determine the presence or absence of other signals on a channel in order to determine if a channel is occupied or clear, respectively. For example, European and Japanese regulations mandate the usage of LBT in the unlicensed bands. Apart from regulatory requirements, carrier sensing via LBT may be one way for fair sharing of the unlicensed spectrum.

In an example embodiment, discontinuous transmission on an unlicensed carrier with limited maximum transmission duration may be enabled. Some of these functions may be supported by one or more signals to be transmitted from the beginning of a discontinuous LAA downlink transmission. Channel reservation may be enabled by the transmission of signals, by an LAA node, after gaining channel access via a successful LBT operation, so that other nodes that receive the transmitted signal with energy above a certain threshold sense the channel to be occupied. Functions that may need to be supported by one or more signals for LAA operation with discontinuous downlink transmission may include one or more of the following: detection of the LAA downlink transmission (including cell identification) by UEs, time & frequency synchronization of UEs, and/or the like.

In an example embodiment, a DL LAA design may employ subframe boundary alignment according to LTE-A carrier aggregation timing relationships across serving cells aggregated by CA. This may not imply that the eNB transmissions can start only at the subframe boundary. LAA may support transmitting PDSCH when not all OFDM symbols are available for transmission in a subframe according to LBT. Delivery of necessary control information for the PDSCH may also be supported.

An LBT procedure may be employed for fair and friendly coexistence of LAA with other operators and technologies operating in an unlicensed spectrum. LBT procedures on a node attempting to transmit on a carrier in an unlicensed spectrum may require the node to perform a clear channel assessment to determine if the channel is free for use. An LBT procedure may involve at least energy detection to determine if the channel is being used. For example, regulatory requirements in some regions, for example, in Europe, may specify an energy detection threshold such that if a node receives energy greater than this threshold, the node assumes that the channel is not free. While nodes may follow such regulatory requirements, a node may optionally use a lower threshold for energy detection than that specified by regulatory requirements. In an example, LAA may employ a mechanism to adaptively change the energy detection threshold. For example, LAA may employ a mechanism to adaptively lower the energy detection threshold from an upper bound. Adaptation mechanism(s) may not preclude static or semi-static setting of the threshold. In an example a Category 4 LBT mechanism or other type of LBT mechanisms may be implemented.

Various example LBT mechanisms may be implemented. In an example, for some signals, in some implementation scenarios, in some situations, and/or in some frequencies, no LBT procedure may performed by the transmitting entity. In an example, Category 2 (for example, LBT without random back-off) may be implemented. The duration of time that the channel is sensed to be idle before the transmitting entity transmits may be deterministic. In an example, Category 3 (for example, LBT with random back-off with a contention window of fixed size) may be implemented. The LBT procedure may have the following procedure as one of its components. The transmitting entity may draw a random number N within a contention window. The size of the contention window may be specified by the minimum and maximum value of N. The size of the contention window may be fixed. The random number N may be employed in the LBT procedure to determine the duration of time that the channel is sensed to be idle before the transmitting entity transmits on the channel. In an example, Category 4 (for example, LBT with random back-off with a contention window of variable size) may be implemented. The transmitting entity may draw a random number N within a contention window. The size of the contention window may be specified by a minimum and maximum value of N. The transmitting entity may vary the size of the contention window when drawing the random number N. The random number N may be employed in the LBT procedure to determine the duration of time that the channel is sensed to be idle before the transmitting entity transmits on the channel.

LAA may employ uplink LBT at the UE. The UL LBT scheme may be different from the DL LBT scheme (for example, by using different LBT mechanisms or parameters), since the LAA UL may be based on scheduled access which affects a UE's channel contention opportunities. Other considerations motivating a different UL LBT scheme include, but are not limited to, multiplexing of multiple UEs in a single subframe.

In an example, a DL transmission burst may be a continuous transmission from a DL transmitting node with no transmission immediately before or after from the same node on the same CC. A UL transmission burst from a UE perspective may be a continuous transmission from a UE with no transmission immediately before or after from the same UE on the same CC. In an example, a UL transmission burst may be defined from a UE perspective. In an example, a UL transmission burst may be defined from an eNB perspective. In an example, in case of an eNB operating DL+UL LAA over the same unlicensed carrier, DL transmission burst(s) and UL transmission burst(s) on LAA may be scheduled in a TDM manner over the same unlicensed carrier. For example, an instant in time may be part of a DL transmission burst or an UL transmission burst.

In an example embodiment, in an unlicensed cell, a downlink burst may be started in a subframe. When an eNB accesses the channel, the eNB may transmit for a duration of one or more subframes. The duration may depend on a maximum configured burst duration in an eNB, the data available for transmission, and/or eNB scheduling algorithm. FIG. 10 shows an example downlink burst in an unlicensed (e.g. licensed assisted access) cell. The maximum configured burst duration in the example embodiment may be configured in the eNB. An eNB may transmit the maximum configured burst duration to a UE employing an RRC configuration message.

The wireless device may receive from a base station at least one message (for example, an RRC) comprising configuration parameters of a plurality of cells. The plurality of cells may comprise at least one license cell and at least one unlicensed (for example, an LAA cell). The configuration parameters of a cell may, for example, comprise configuration parameters for physical channels, (for example, a ePDCCH, PDSCH, PUSCH, PUCCH and/or the like).

Frame structure type 3 may be applicable to an unlicensed (for example, LAA) secondary cell operation. In an example, frame structure type 3 may be implemented with normal cyclic prefix only. A radio frame may be T_(f)=307200·T_(s)=10 ms long and may comprise 20 slots of length T_(slot)=15360·T_(s)=0.5 ms, numbered from 0 to 19. A subframe may be defined as two consecutive slots where subframe i comprises of slots 2i and 2i+1. In an example, the 10 subframes within a radio frame may be available for downlink and/or uplink transmissions. Downlink transmissions may occupy one or more consecutive subframes, starting anywhere within a subframe and ending with the last subframe either fully occupied or following one of the DwPTS durations in a 3GPP Frame structure 2 (TDD frame). When an LAA cell is configured for uplink transmissions, frame structure 3 may be used for both uplink or downlink transmission.

An eNB may transmit one or more RRC messages to a wireless device (UE). The one or more RRC messages may comprise configuration parameters of a plurality of cells comprising one or more licensed cells and/or one or more unlicensed (for example, Licensed Assisted Access-LAA) cells. The one or more RRC messages may comprise configuration parameters for one or more unlicensed (for example, LAA) cells. An LAA cell may be configured for downlink and/or uplink transmissions.

In an example, the configuration parameters may comprise a first configuration field having a value of N for an LAA cell. The parameter N may be RRC configurable. N may be a cell specific or a UE specific RRC parameter. For example, N (for example, 6, 8, 16) may indicate a maximum number of HARQ processes that may be configured for UL transmissions. In an example, one or more RRC messages may comprise configuration parameters of multi-subframe allocation parameters, maximum number of HARQ processes in the uplink, and/or other parameters associated with an LAA cell.

In an example, a UE may receive a downlink control information (DCI) indicating uplink resources (resource blocks for uplink grant) for uplink transmissions.

In an example embodiment, persistent (also called burst or multi-subframe) scheduling may be implemented. An eNB may schedule uplink transmissions by self scheduling and/or cross scheduling. In an example, an eNB may use UE C-RNTI for transmitting DCIs for multi-subframe grants. A UE may receive a multi-subframe DCI indicating uplink resources (resource blocks for uplink grant) for more than one consecutive uplink subframes (a burst), for example m subframes. In an example, a UE may transmit m subpackets (transport blocks-TB s), in response to the DCI grant. FIG. 11 shows an example multi-subframe grant, LBT process, and multi-subframe transmission.

In an example embodiment, an uplink DCI may comprise one or more fields including uplink RBs, a power control command, an MCS, the number of consecutive subframes (m), and/or other parameters for the uplink grant.

In an example, a multi-subframe DCI may comprise one or more parameters indicating that a DCI grant is a multi-subframe grant. A field in a multi-subframe DCI may indicate the number of scheduled consecutive subframes (m). For example, a DCI for an uplink grant on an LAA cell may comprise a 3-bit field. The value indicated by the 3-bit field may indicate the number of subframes associated with the uplink DCI grant (other examples may comprise, for example, a 1-bit field or a 2-bit field). For example, a value 000 may indicate a dynamic grant for one subframe. For example, a field value 011 may indicate a DCI indicating uplink resources for 4 scheduled subframes (m=field value in binary+1). In an example, RRC configuration parameters may comprise a first configuration field having a value of N for an LAA cell. In an example implementation, the field value may be configured to be less than N. For example, N may be configured as 2, and a maximum number of scheduled subframes in a multi-subframe grant may be 2. In an example, N may be configured as 4 and a maximum number of scheduled subframes in a multi-subframe grant may be 4. In an example, N may be a number of configured HARQ processes in an UL. Successive subframes on a carrier may be allocated to a UE when the UE receives a multi-subframe UL DCI grant from an eNB.

At least one field included in a multi-subframe DCI may determine transmission parameters and resource blocks used across m consecutive subframes for transmission of one or more TBs. The DCI may comprise an assignment of a plurality of resource blocks for uplink transmissions. The UE may use the RBs indicated in the DCI across m subframes. The same resource blocks may be allocated to the UE in m subframes as shown in FIG. 11.

A UE may perform listen before talk (LBT) before transmitting uplink signals. The UE may perform an LBT procedure indicating that a channel is clear for a starting subframe of the one or more consecutive uplink subframes. The UE may not perform a transmission at the starting subframe if the LBT procedure indicates that the channel is not clear for the starting subframe.

In an example embodiment, a wireless device may receive one or more radio resource control (RRC) messages comprising configuration parameters for a licensed assisted access (LAA) cell. The one or more RRC messages may comprise one or more consecutive uplink subframe allocation configuration parameters. In an example, the one or more consecutive uplink subframe allocation configuration parameters comprises a first field, N.

A wireless device may receive a downlink control information (DCI) indicating uplink resources in a number of one or more consecutive uplink subframes of the LAA cell. The DCI may comprise: the number of the one or more consecutive uplink subframes (m); an assignment of a plurality of resource blocks; and a transmit power control command. The first field may indicate an upper limit for the number of the one or more consecutive uplink subframes.

The wireless device may perform a listen before talk procedure indicating that a channel is clear for a starting subframe of the one or more consecutive uplink subframes. The wireless device may transmit one or more transport blocks, via the plurality of resource blocks used across the one or more consecutive uplink subframes. At least one field included in a multi-subframe DCI may determine transmission parameters and resource blocks used across m consecutive subframes for transmission of one or more TBs. The DCI may comprise an assignment of a plurality of resource blocks for uplink transmissions. The UE may use the RBs indicated in the DCI across m subframes. The same resource blocks may be allocated to the UE in m subframes.

A DCI indicating a multi-subframe grant (MSFG) may be supported in carrier aggregation, for example, for an unlicensed cell (e.g. an LAA cell). Design of a multi-subframe grant (MSFG) may take into account the design of existing DCIs used for single subframe grants. For example, current LTE-A DCI Format 0 and 4 may be used for uplink grants with and without special multiplexing. DCI Format 0 and 4 may be updated to support MSFGs with or without special multiplexing.

A MSFG may allow a UE to transmit on multiple consecutive uplink subframes based on some common set of transmission parameters. Some of transmission parameters, like MCS level, power control command, and/or resource assignments (e.g. RBs) may be common across scheduled subframes. Some parameters, like HARQ process ID, RV and/or NDI may be subframe specific. The DCI indicating a MSFG may comprise one or more parameters indicating the number of consecutive subframes allowed for transmission according to the grant. In an example, the parameters which may be configured by DCI may include the number of consecutive subframes (m) associated with the MSFG. A MSFG may provide resource allocation for subframes starting from subframe n and ending at subframe n+m−1.

When a UE receives a multi-subframe grant (MSFG) for UL transmissions of m consecutive subframes on an LAA carrier, the UE may perform LBT before transmission on the scheduled subframes. A successful LBT may be followed by a reservation signal if transmission of the reservation signals is allowed and/or needed. The UE's LBT may or may not succeed before start of a first allowed transmission symbol of subframe n. In an example, if UE's LBT is successful before a first allowed transmission symbol of subframe n, the UE may transmit data according to multi-subframe DCI. The UE may transmit data (TBs) when LBT is successful.

The DCI indicating a MSFG may include parameters for UEs behavior due to LBT. A multi-subframe DCI may include possible LBT time interval(s) and/or at least one LBT configuration parameter. The DCI may indicate one or more configuration parameters for LBT process before transmissions corresponding to a MSFG.

In an example, one or more DCI may indicate configuration for transmission of reservation signals, format of reservation signals, allowed starting symbol, and/or LBT intervals/symbols associated with a MSFG. For example, the DCI may indicate a PUSCH starting position in a subframe. LBT procedure may be performed before the PUSCH starting position. One or more DCI may comprise configuration parameters indicating reservation signals and/or partial subframe configuration. In an example embodiment, transmission of reservation signals and/or partial subframe for a multi-subframe grant may not be supported.

In an example, a UE may perform LBT (e.g. in a symbol) before subframe n starts. In an example, a UE may perform LBT in a first symbol of subframe n. A UE may be configured to perform LBT in one or more allowed symbols of a subframe, or within a configured period/interval in a subframe. The multi-subframe grant DCI may include possible LBT time interval(s) and/or at least one LBT configuration parameter. For example, DCI may indicate that PUSCH starts in symbol 0 and a LBT procedure is performed before PUSCH starts (e.g. last symbol of a previous subframe). For example, DCI may indicate that PUSCH starts in symbol 1 and an LBT procedure is performed before PUSCH starts (e.g. in symbol 0).

In an example, one or more LBT configuration parameters may be indicated in an RRC message. In an example, one or more RRC message configuring an LAA cell may comprise at least one field indicating an LBT interval.

An eNB may transmit to a UE one or more RRC messages comprising configuration parameters of a plurality of cells. The plurality of cells may comprise one or more licensed cell and one or more unlicensed (e.g. LAA) cells. The eNB may transmit one or more DCIs for one or more licensed cells and one or more DCIs for unlicensed (e.g. LAA) cells to schedule downlink and/or uplink TB transmissions on licensed/LAA cells.

A UE may receive at least one downlink control information (DCI) from an eNB indicating uplink resources in m subframes of a licensed assisted access (LAA) cell. In an example embodiment, an MSFG DCI may include information about RV, NDI and HARQ process ID of a subframe of the grant. For example, when a grant is for m subframes, the grant may include at least m set of RVs and NDIs for HARQ processes associated with m subframes in the grant. In an example, subframe specific parameters may comprise one or more of the following for each subframe of a MSFG burst: M bits for RV, example 2 bits for 4 redundancy versions; and/or 1 bit for NDI.

In an example, common parameters may include: TPC for PUSCH, Cyclic shift for DM RS, resource block assignment, MCS and/or spatial multiplexing parameters (if any, for example included in DCI format 4), LBT related parameters applied to the uplink burst, and/or Other parameters, e.g. one or more multi-subframe configuration parameters. The MSFG DCI may comprise an RB assignment field, an MCS field, an TPC field, an LBT field applicable to all the subframes associated with a MSFG. These parameters may be the same for different subframes of a MSFG burst. Resource block assignment, MCS and/or spatial multiplexing parameters may change from one MSFG burst to another MSFG burst.

In an example embodiment, an uplink MSFG DCI may further comprise a channel state request flag. Channel-state request flag (1, 2 or 3 bits). The network may explicitly request an aperiodic channel-state report to be transmitted on the UL-SCH by setting this bit(s) in the uplink grant. In the case of carrier aggregation, 2 or 3 bits may be used to indicate which downlink component carrier the CSI should be reported for.

For aperiodic CSI reporting, one or more CSI request bits (e.g. 1, 2 or 3 bits) in a downlink control signaling may allow for multiple different types of CSI reports to be requested (a bit combination may represent no CSI request). An eNB may transmit a DCI including CSI request bits to a UE. A first value of the CSI request field in the DCI may trigger one or more CSI reports for the downlink component carrier associated with the uplink component carrier for which the scheduling grant relates to. A CSI request may be for one of multiple configurable combinations of component carriers/CSI processes. As an example, for a UE configured with two or more downlink component carriers, aperiodic reports may be requested for the primary component carrier, one or more secondary component carrier, or both. An eNB may transmit to a UE one or more messages (e.g. RRC messages) comprising configuration parameters of one or more cells including one or more LAA cells. The one or more messages may comprise CSI configuration parameters.

Some example RRC configuration parameters for CSI and CQI configurations are shown below. Implementation of some of the parameters may be optional. For example, RRC configuration parameters may comprise configuration parameters for one or more CSI processes, CSI reference signal (RS) radio resources and CSI interference measurement (IM) radio resources. RRC configuration parameters provide semi-static configuration for the CSI parameters. The configuration parameters may associate a CSI process to one or more CSI RS and/or one or more CSI IMs. Aperiodic CSI configuration parameters for example may include aperiodicCSI-Trigger indicating for which serving cell(s) the aperiodic CSI report is triggered when one or more SCells are configured. Aperiodic CSI configuration parameters for example may include an altCQI-Table IE indicating the applicability of the alternative CQI table for both aperiodic and periodic CSI reporting for the concerned serving cell. Aperiodic CSI configuration parameters for example may include cqi-ReportModeAperiodic indicating one or more aperiodic report modes. Additional example CSI configuration parameters are disclosed in 3GPP standard document TS 36.331.

An eNB may transmit an uplink MSFG DCI for one or more LAA cells. There is a need to define the UE behavior when a MSFG is transmitted to a UE triggering transmission of an aperiodic CSI request. When a CSI request is included in a MSFG DCI, the UE may transmit aperiodic CSI. CSI transmission in every subframe of a MSFG may reduce uplink transmission efficiency. Example embodiments introduce mechanisms for transmission of aperiodic CSI when aperiodic CSI is triggered via a MSFG DCI. Example embodiments enhances uplink CSI transmission and improves uplink spectral efficiency by defining a mechanism for transmitting CSI in one of the many subframes associated with a MSFG DCI. Example embodiments may determine which one of MSFG subframe(s) is employed for aperiodic transmission. DCI signaling is used to dynamically configure/determine the CSI subframe. Example embodiments describe UE behavior regarding aperiodic CSI transmission considering an un-deterministic outcome of an LBT procedure for a subframe. Example embodiments define rules for transmission of CSI depending on the DCI and an LBT procedure in response to a MSFG DCI that triggers aperiodic CSI transmission.

In an example embodiment, an eNB may transmit a DCI (MSFG DCI) indicating uplink resources in a number of one or more consecutive uplink subframes of the LAA cell. The MSFG DCI may comprise a CSI request field. The MSFG DCI may comprise a field indicating which one of the subframes in the uplink MSFG burst may include aperiodic CSI report.

The UE may determine a position of a first subframe in the one or more consecutive uplink subframes (associated with the MSFG) employing the first field. The wireless device may transmit in the first subframe one or more CSI fields of the aperiodic CSI of an LAA cell when the CSI request field is set to trigger a CSI request (indicates that aperiodic CSI is triggered) and when the wireless device is allowed to transmit in the first subframe according to an LBT procedure. The MSFG DCI may comprise one or more fields indicating one or more configuration parameters of the LBT procedure for the MSFG, e.g., LBT type, LBT symbol, and/or LBT priority class. In an example embodiment, an eNB may indicate which subframe may be employed for CSI transmission. This implementation may provide additional flexibility for configuring a subframe for CSI transmission. A CSI request may be applied to a preconfigured subframe within the burst. The subframe may be indicated by a field in the DCI. For example, a 3 bit field may be included in the DCI indicating an offset from the first scheduled subframe. In an example, a field in the DCI may indicate the number of one or more subframes associated with a MSFG and the position of the subframe (in the one or more subframe) that is employed for aperiodic CSI transmission.

In an example embodiment, a MSFG DCI may indicate that aperiodic CSI is configured for transmission in a first subframe of the m consecutive subframe associated with the MSFG DCI. If the first subframe indicated by a MSFG DCI does not include an uplink TB, e.g. because the UE does not indicate a clear channel in the first subframe, the CSI may not be transmitted in other subframes. The UE may not transmit the requested CSI configured for transmission in the first subframe, when the first subframe of the MSFG is not clear based on LBT.

For example, a MSFG DCI may indicate that aperiodic CSI is configured for transmission in subframe n of the m consecutive subframe associated with the MSFG DCI. The UE may start LBT for transmission in subframe n. If LBT indicates a clear channel for transmission in subframe n, the UE may transmit the aperiodic CSI in subframe n. In an example, if the LBT does not indicate a clear channel until subframe n+2. The UE may not transmit aperiodic CSI as triggered by the MSFG DCI, since the UE opportunity for transmission of aperiodic CSI in subframe n is lost.

In an example embodiment, a MSFG DCI may indicate that aperiodic CSI is configured for transmission in a last subframe of the m consecutive subframe associated with the MSFG DCI. The CSI request may be applied to the last scheduled subframe associated with the MSFG. The first subframe of a MSFG may not be cleared for an uplink transmission depending on LBT outcome. The UE may transmit aperiodic CSI requested by an eNB in the last subframe of the MSFG. This implementation mechanism may reduce the probability of CSI dropping. The timing of the aperiodic CSI transmission may be closer to the next possible downlink/uplink grant transmitted by an eNB. The CSI may include more useful information if it is transmitted in the last subframe of a MSFG. For example, if an uplink MSFG burst includes 10 subframes, and if CSI is transmitted in the first subframe, the CSI may not include useful information for an eNB for subsequent grants. Channel condition may change after 10 subframes.

The interpretation of CSI request bits may be similar to aperiodic CSI configuration for a licensed carrier. An example implementation of configuration of CSI bits is described below. Implementation of some of the features may be optional.

In an example embodiment, the term “UL/DL configuration” may refer to the higher layer parameter subframeAssignment. A UE may perform aperiodic CSI reporting using the PUSCH in subframe n+k on serving cell C, upon decoding in subframe n either: an uplink DCI format, or a Random Access Response Grant, for serving cell C if the respective CSI request field is set to trigger a report and is not reserved.

In an example embodiment, if the CSI request field is 1 bit and the UE is configured in transmission mode 1-9 and the UE is not configured with csi-SubframePatternConfig-r12 for any serving cell, a report is triggered for serving cell C, if the CSI request field is set to ‘1’.

In an example embodiment, if the CSI request field is 1 bit and the UE is configured in transmission mode 10 and the UE is not configured with csi-SubframePatternConfig-r12 for any serving cell, a report is triggered for a set of CSI process(es) for serving cell corresponding to the higher layer configured set of CSI process(es) associated with the value of CSI request field of ‘01’ in FIG. 22, if the CSI request field is set to ‘1’.

In an example embodiment, if the CSI request field size is 2 bits and the UE is configured in transmission mode 1-9 for serving cells and the UE is not configured with csi-SubframePatternConfig-r12 for any serving cell, a report is triggered according to the value in FIG. 21 corresponding to aperiodic CSI reporting.

In an example embodiment, if the CSI request field size is 2 bits and the UE is configured in transmission mode 10 for at least one serving cell and the UE is not configured with csi-SubframePatternConfig-r12 for any serving cell, a report is triggered according to the value in FIG. 22 corresponding to aperiodic CSI reporting.

In an example embodiment, if the CSI request field is 1 bit and the UE is configured with the higher layer parameter csi-SubframePatternConfig-r12 for at least one serving cell, a report is triggered for a set of CSI process(es) and/or {CSI process, CSI subframe set}-pair(s) for serving cell C corresponding to the higher layer configured set of CSI process(es) and/or {CSI process, CSI subframe set}-pair(s) associated with the value of CSI request field of ‘01’ in FIG. 23, if the CSI request field is set to ‘1’.

In an example embodiment, if the CSI request field size is 2 bits and the UE is configured with the higher layer parameter csi-SubframePatternConfig-r12 for at least one serving cell, a report is triggered according to the value in FIG. 23 corresponding to aperiodic CSI reporting.

In an example embodiment, if the CSI request field size is 3 bits and the UE is not configured with the higher layer parameter csi-SubframePatternConfig-r12 for any serving cell, a report is triggered according to the value in FIG. 24 corresponding to aperiodic CSI reporting.

In an example embodiment, if the CSI request field size is 3 bits and the UE is configured with the higher layer parameter csi-SubframePatternConfig-r12 for at least one serving cell, a report is triggered according to the value in FIG. 25 corresponding to aperiodic CSI reporting.

In an example, for a given serving cell, if the UE is configured in transmission modes 1-9, the “CSI process” in FIG. 22, FIG. 23, FIG. 24, and FIG. 25 refers to the aperiodic CSI configured for the UE on the given serving cell. A UE is not expected to be configured by higher layers with more than 5 CSI processes in each of the 1st and 2nd set of CSI process(es) in FIG. 22. A UE is not expected to be configured by higher layers with more than 5 CSI processes and/or {CSI process, CSI subframe set}-pair(s) in each of the 1st and 2nd set of CSI process(es) and/or {CSI process, CSI subframe set}-pair(s) in FIG. 23. A UE is not expected to be configured by higher layers with more than one instance of the same CSI process in each of the higher layer configured sets associated with the value of CSI request field of ‘01’, ‘10’, and ‘11’ in FIG. 22 and FIG. 23 respectively. A UE is not expected to be configured by higher layers with more than 32 CSI processes in each of the 1st to 6th set of CSI process(es) in FIG. 24. A UE is not expected to be configured by higher layers with more than 32 CSI processes and/or {CSI process, CSI subframe set}-pair(s) in each of the 1st to 6th set of CSI process(es) and/or {CSI process, CSI subframe set}-pair(s) in FIG. 25. A UE is not expected to be configured by higher layers with more than one instance of the same CSI process in each of the higher layer configured sets associated with the value of CSI request field of ‘001’, ‘010’, ‘011’, ‘100’, ‘101’, ‘110’ and ‘111’ in FIG. 24 and FIG. 25 respectively.

A UE is not expected to receive more than one aperiodic CSI report request for a given subframe.

If a UE is configured with more than one CSI process for a serving cell, the UE on reception of an aperiodic CSI report request triggering a CSI report according to FIG. 22 is not expected to update CSI corresponding to the CSI reference resource for all CSI processes except the max(N_(x)−N_(u), 0) lowest-indexed CSI processes for the serving cell associated with the request when the UE has N_(u) unreported CSI processes associated with other aperiodic CSI requests for the serving cell, where a CSI process associated with a CSI request may only be counted as unreported in a subframe before the subframe where the PUSCH carrying the corresponding CSI is transmitted, and N_(CSI-P) is the maximum number of CSI processes supported by the UE for the serving cell and: for FDD serving cell N_(x)=N_(CSI-P); for TDD serving cell: if the UE is configured with four CSI processes for the serving cell, N_(x)=N_(CSI-P); if the UE is configured with two or three CSI processes for the serving cell, N_(x)−3.

If more than one value of N_(CSI-P) is included in the UE-EUTRA-Capability, the UE assumes a value of N_(CSI-P) that is consistent with its CSI process configuration. If more than one consistent value of N_(CSI-P) exists, the UE may assume any one of the consistent values.

If a UE is configured with multiple cell groups, and if the UE receives multiple aperiodic CSI report requests in a subframe for different cell groups triggering more than one CSI report, the UE is not required to update CSI for more than 5 CSI processes from the CSI processes corresponding to all the triggered CSI reports.

If a UE is configured with a PUCCH-SCell, and if the UE receives multiple aperiodic CSI report requests in a subframe for both the primary PUCCH group and the secondary PUCCH group triggering more than one CSI report, the UE is not required to update CSI for more than 5 CSI processes from the CSI processes corresponding to all the triggered CSI reports, in case the total number of serving cells in the primary and secondary PUCCH group is no more than 5. If a UE is configured with more than 5 serving cells, and if the UE receives aperiodic CSI report request in a subframe triggering more than N_(y) CSI reports, the UE is not required to update CSI for more than N_(y) CSI processes from the CSI processes corresponding to all the triggered CSI reports, where the value of N_(y) is given by maxNumberUpdatedCSI-Proc-r13.

In an example, the minimum reporting interval for aperiodic reporting of CQI and PMI and RI and CRI may be 1 subframe. The subband size for CQI may be the same for transmitter-receiver configurations with and without precoding.

According to various embodiments, a device such as, for example, a wireless device, a base station and/or the like, may comprise one or more processors and memory. The memory may store instructions that, when executed by the one or more processors, cause the device to perform a series of actions. Embodiments of example actions are illustrated in the accompanying figures and specification.

FIG. 13 is an example flow diagram as per an aspect of an embodiment of the present disclosure. At 1310, a wireless device may receive one or more radio resource control (RRC) messages comprising configuration parameters for a licensed assisted access (LAA) cell. The configuration parameters may comprise one or more channel state information (CSI) parameters. At 1320, the wireless device may receive a downlink control information (DCI) indicating uplink resources in a number of one or more consecutive uplink subframes of the LAA cell. The DCI may comprise a first field, a second field, and one or more third fields. At 1330, the wireless device may determine a position of a first subframe in the one or more consecutive uplink subframes employing the first field. At 1340, the wireless device may transmit, in the first subframe, one or more CSI fields of the LAA cell when: the second field is set to trigger a CSI report; and the wireless device is allowed to transmit in the first subframe according to a listen-before-talk (LBT) procedure based, at least, on the one or more third fields.

The one or more CSI fields may, for example, be associated with one or more CSI processes identified based, at least in part, on the second field. The one or more CSI fields may, for example, be associated with one or more CSI processes identified based, at least in part, on the one or more RRC messages. The configuration parameters may, for example, comprise one or more CSI reference signal (CSI-RS) radio resource parameters and one or more CSI interference measurement (CSI-IM) resource parameters. The DCI may indicate, for example, the number of the one or more consecutive uplink subframes. At least one of the one or more third fields may indicate, for example, one or more LBT procedure configuration parameters. The CSI fields may comprise, for example, a channel quality index (CQI), a precoding matrix indicator (PMI) and a rank indicator (RI). The wireless device may, for example, further perform measurements in one or more second subframes according to a subframe pattern configuration. The configuration parameters may indicate the subframe pattern configuration. The DCI may further comprise, for example, a fourth field indicating a resource block assignment for transmitting the one or more CSI fields. The DCI may further comprise, for example, a transmit power control (TPC) employed for calculating a transmit power for transmission of the one or more CSI fields.

FIG. 14 is an example flow diagram as per an aspect of an embodiment of the present disclosure. At 1410, a base station may transmit a downlink control information (DCI) indicating uplink resources in one or more subframes. The DCI may comprise a first field and a second field. At 1420 the base station may receive in a first subframe, one or more channel state information (CSI) fields when the second field is set to trigger a CSI report. A position of the first subframe in the one or more subframes may depend, at least, on a value of the first field. The one or more CSI fields may comprise, for example, a channel quality index (CQI), a precoding matrix indicator (PMI) and a rank indicator (RI).

FIG. 15 is an example flow diagram as per an aspect of an embodiment of the present disclosure. At 1510, a wireless device may receive a downlink control information (DCI) indicating uplink resources in a number of one or more consecutive uplink subframes of a licensed assisted access (LAA) cell. The DCI may comprise a first field, a second field, and one or more third fields. At 1520, the wireless device may determine a position of a first subframe in the one or more consecutive uplink subframes employing the first field. At 1530, the wireless device may transmit, in the first subframe, one or more channel state information (CSI) fields of the LAA cell when, for example: the second field is set to trigger a CSI report; and/or the wireless device is allowed to transmit in the first subframe according to a listen-before-talk (LBT) procedure based, at least, on at least one of the one or more third fields.

FIG. 16 is an example flow diagram as per an aspect of an embodiment of the present disclosure. At 1610, a base station may transmit a downlink control information (DCI) indicating uplink resources in a number of one or more consecutive uplink subframes of a licensed assisted access (LAA) cell. The DCI may comprise a first field, a second field, and one or more third fields. At 1620, the base station may determine a position of a first subframe in the one or more consecutive uplink subframes employing the first field. At 1630, the base station may receive, in the first subframe, one or more channel state information (CSI) fields of the LAA cell when, for example: the second field is set to trigger a CSI report, and/or the wireless device is allowed to transmit in the first subframe according to a listen-before-talk (LBT) procedure based, at least, on at least one of the one or more third fields.

FIG. 17 is an example flow diagram as per an aspect of an embodiment of the present disclosure. At 1710, a wireless device may receive a downlink control information (DCI) comprising a first field and a second field. At 1720, the wireless device may determine a position of a first subframe in one or more subframes employing the first field. At 1730, the wireless device may transmit, in the first subframe, one or more channel state information (CSI) fields when the second field is set to trigger a CSI report.

FIG. 18 is an example flow diagram as per an aspect of an embodiment of the present disclosure. At 1810, a base station may transmit a downlink control information (DCI) comprising a first field and a second field. At 1820, the base station may determine a position of a first subframe in one or more subframes employing the first field. At 1830, the base station may receive, in the first subframe, one or more channel state information (CSI) fields when the second field is set to trigger a CSI report.

FIG. 19 is an example flow diagram as per an aspect of an embodiment of the present disclosure. At 1910, a wireless device may receive a downlink control information: indicating uplink resources in one or more subframes, triggering a channel state information (CSI) report, and comprising a first field. At 1920, the wireless device may determine a position of a subframe in one or more subframes employing the first field. At 1930, the wireless device may transmit one or more CSI fields in the subframe.

FIG. 20 is an example flow diagram as per an aspect of an embodiment of the present disclosure. At 2010, a base station may transmit a downlink control information: indicating uplink resources in one or more subframes, triggering a channel state information (CSI) report, and comprising a first field. At 2020, the base station may determine a position of a subframe in one or more subframes employing the first field. At 2030, the base station may receive one or more CSI fields in the subframe.

In this specification, “a” and “an” and similar phrases are to be interpreted as “at least one” and “one or more.” In this specification, the term “may” is to be interpreted as “may, for example.” In other words, the term “may” is indicative that the phrase following the term “may” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. If A and B are sets and every element of A is also an element of B, A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, possible subsets of B={cell1, cell2} are: {cent}, {cell2}, and {cell1, cell2}.

In this specification, parameters (Information elements: IEs) may comprise one or more objects, and each of those objects may comprise one or more other objects. For example, if parameter (IE) N comprises parameter (IE) M, and parameter (IE) M comprises parameter (IE) K, and parameter (IE) K comprises parameter (information element) J, then, for example, N comprises K, and N comprises J. In an example embodiment, when one or more messages comprise a plurality of parameters, it implies that a parameter in the plurality of parameters is in at least one of the one or more messages, but does not have to be in each of the one or more messages.

Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an isolatable element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (i.e hardware with a biological element) or a combination thereof, all of which are behaviorally equivalent. For example, modules may be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab or the like) or a modeling/simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. Additionally, it may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and/or quantum hardware. Examples of programmable hardware comprise: computers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers and microprocessors are programmed using languages such as assembly, C, C++ or the like. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDL) such as VHSIC hardware description language (VHDL) or Verilog that configure connections between internal hardware modules with lesser functionality on a programmable device. Finally, it needs to be emphasized that the above mentioned technologies are often used in combination to achieve the result of a functional module.

The disclosure of this patent document incorporates material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, for the limited purposes required by law, but otherwise reserves all copyright rights whatsoever.

While various embodiments have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the spirit and scope. In fact, after reading the above description, it will be apparent to one skilled in the relevant art(s) how to implement alternative embodiments. Thus, the present embodiments should not be limited by any of the above described exemplary embodiments. In particular, it should be noted that, for example purposes, the above explanation has focused on the example(s) using FDD communication systems. However, one skilled in the art will recognize that embodiments of the disclosure may also be implemented in a system comprising one or more TDD cells (e.g. frame structure 2 and/or frame structure 3-licensed assisted access). The disclosed methods and systems may be implemented in wireless or wireline systems. The features of various embodiments presented in this disclosure may be combined. One or many features (method or system) of one embodiment may be implemented in other embodiments. Only a limited number of example combinations are shown to indicate to one skilled in the art the possibility of features that may be combined in various embodiments to create enhanced transmission and reception systems and methods.

In addition, it should be understood that any figures which highlight the functionality and advantages, are presented for example purposes only. The disclosed architecture is sufficiently flexible and configurable, such that it may be utilized in ways other than that shown. For example, the actions listed in any flowchart may be re-ordered or only optionally used in some embodiments.

Further, the purpose of the Abstract of the Disclosure is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract of the Disclosure is not intended to be limiting as to the scope in any way.

Finally, it is the applicant's intent that only claims that include the express language “means for” or “step for” be interpreted under 35 U.S.C. 112. Claims that do not expressly include the phrase “means for” or “step for” are not to be interpreted under 35 U.S.C. 112. 

What is claimed is:
 1. A method comprising: receiving, by a wireless device, one or more radio resource control (RRC) messages comprising configuration parameters for a licensed assisted access (LAA) cell, the configuration parameters comprising one or more channel state information (CSI) parameters; receiving a downlink control information (DCI) indicating uplink resources in a number of one or more consecutive uplink subframes of the LAA cell, the DCI comprising a first field, a second field, and one or more third fields; determining a position of a first subframe in the one or more consecutive uplink subframes employing the first field; and transmitting, in the first subframe, one or more CSI fields of the LAA cell when: the second field is set to trigger a CSI report; and the wireless device is allowed to transmit in the first subframe according to a listen-before-talk (LBT) procedure based, at least, on the one or more third fields.
 2. The method of claim 1, wherein the one or more CSI fields are associated with one or more CSI processes identified based, at least in part, on the second field.
 3. The method of claim 1, wherein the one or more CSI fields are associated with one or more CSI processes identified based, at least in part, on the one or more RRC messages.
 4. The method of claim 1, wherein the configuration parameters comprise one or more CSI reference signal (CSI-RS) radio resource parameters and one or more CSI interference measurement (CSI-IM) resource parameters.
 5. The method of claim 1, wherein the DCI indicates the number of the one or more consecutive uplink subframes.
 6. The method of claim 1, wherein at least one of the one or more third fields indicates one or more LBT procedure configuration parameters.
 7. The method of claim 1, wherein the CSI fields comprise a channel quality index (CQI), a precoding matrix indicator (PMI) and a rank indicator (RI).
 8. The method of claim 1, further comprising performing measurements in one or more second subframes according to a subframe pattern configuration, wherein the configuration parameters indicate the subframe pattern configuration.
 9. The method of claim 1, wherein the DCI further comprises a fourth field indicating a resource block assignment for transmitting the one or more CSI fields.
 10. The method of claim 1, wherein the DCI further comprises a transmit power control (TPC) employed for calculating a transmit power for transmission of the one or more CSI fields.
 11. A wireless device comprising: one or more processors; and memory storing instructions that, when executed by the one or more processors, cause the wireless device to: receive one or more radio resource control (RRC) messages comprising configuration parameters for a licensed assisted access (LAA) cell, the configuration parameters comprising one or more channel state information (CSI) parameters; receive a downlink control information (DCI) indicating uplink resources in a number of one or more consecutive uplink subframes of the LAA cell, the DCI comprising a first field, a second field, and one or more third fields; determine a position of a first subframe in the one or more consecutive uplink subframes employing the first field; and transmit, in the first subframe, one or more CSI fields of the LAA cell when: the second field is set to trigger a CSI report; and the wireless device is allowed to transmit in the first subframe according to a listen-before-talk (LBT) procedure based, at least, on the one or more third fields.
 12. The wireless device of claim 11, wherein the one or more CSI fields are associated with one or more CSI processes identified based, at least in part, on the second field.
 13. The wireless device of claim 11, wherein the one or more CSI fields are associated with one or more CSI processes identified based, at least in part, on the one or more RRC messages.
 14. The wireless device of claim 11, wherein the configuration parameters comprise one or more CSI reference signal (CSI-RS) radio resource parameters and one or more CSI interference measurement (CSI-IM) resource parameters.
 15. The wireless device of claim 11, wherein the DCI indicates the number of the one or more consecutive uplink subframes.
 16. The wireless device of claim 11, wherein at least one of the one or more third fields indicates one or more LBT procedure configuration parameters.
 17. The wireless device of claim 11, wherein the CSI fields comprise a channel quality index (CQI), a precoding matrix indicator (PMI) and a rank indicator (RI).
 18. The wireless device of claim 11, the instructions, when executed by the one or more processors, further cause the wireless device to perform measurements in one or more second subframes according to a subframe pattern configuration, wherein the configuration parameters indicate the subframe pattern configuration. 